The present invention relates to a method and signal processing means for detecting and discriminating between natural and structural layers encountered during the terra-flight of kinetic energy vehicles. Kinetic energy vehicles in terra-flight (terra-craft) utilize their kinetic energy to traverse the layers of a structure or geologic media. The present invention is based on the very creative but non-intuitive postulate that peak g-s (that is the peak rate of velocity removal from a terra-dynamic system) is totally dependent on the material encountered during flight and the geometry of the terra-craft. Therefore, each material for a given craft geometry has a unique deceleration value, independent of the velocity of the craft. In practice, this unique value for each material is a very narrow band of values.
The present invention takes advantage of this postulate by generating the deceleration value for each layer of material through which a terra-craft travels, which value can then be compared to government acceleration data of various kinetic energy projectiles taken for geological penetration technology. This government data has been gathered for over five decades, and velocity-specific information therefrom is used for purposes of understanding what loading a penetrating projectile undergoes at very high deceleration, to ensure that the projectile design is appropriate for purposes of traversing known layers of geological media. The present invention allows a new usage of this data (free from velocity values) derived from this multi-million dollar governmental test effort, to the benefit of extraterrestrial exploration or remote monitoring of hazardous locations such as volcanoes and sea beds. Furthermore, it is a novel method of detecting and identifying unknown layers of a geological media or concealed structure.
The signal processing means of the present invention utilizes a pseudo auto-correlation of the deceleration signal to separate different types of layers encountered by the terra-craft, leading to excellent sensitivity to distinguish between a wide range of material densities (and, with greater sensitivity, more information regarding the material make-up of each layer can be identified).
Therefore, the signal processing means of the present invention is especially beneficial in the exploration of geological formations (such as mountains, volcanoes etc.) or extraterrestrial bodies, to determine the layer structure thereof (identity hardness and, in some embodiments, depth of each layer), thereby providing critical information to determine the makeup and origin of the formation or body, and if desirable enable the accurate placement of sensors in particular layers there-within.
A terra-craft system traverses manmade protective and/or geologic media via its kinetic energy, in similar fashion to an aircraft traversing the atmospheric medium of terrestrial or extra-terrestrial bodies. The phrase “terra-dynamics” has been coined to imply the system's direct association to the field of aerodynamics. The principle difference being that a terra-dynamic system encounters many and varied media during its flight. Aero-dynamic media is restricted to the atmospheric make up of a celestial body.
Current sensor placement and munitions systems in geological exploration and military applications typically function via an electronic timer circuit installed on a terra-craft. The setting of this timer is determined by a specialist's educated guess, which in turn is based on the system geometry and available intelligence gathered on the structural characteristics of the target. Where no good intelligence is available, the timer setting becomes imprecise. The imprecision produces on-board functions at undesirable spatial locations, severely or totally diminishing the system effectiveness, requiring target re-strike with associated additional human and material exposure. Some devices will actuate with a proximity or acceleration sensor, or a timer coupled with a sensor. These devices are similarly limited to an educated guess as to how hard a target layer is or when (at what time) the terra-craft will reach a certain station.
However, even when a layer structure is known or suspected, this educated guess as to when a fuze or sensor should be actuated is fraught with problems; for example, concrete increases in hardness over time. This increase is non-linear so that a terra-craft will reach a different station at different times depending on the date at which the structure is approached. When a structure's geometry or layer structure is unknown, “educated guesses” frequently result in the inaccurate placement of sensors (or detonation of munitions), requiring the use of additional resources to repeat the placement.
In U.S. Application Publication No. 2006/0090663 (“Biggs”), a layer detection system is generally disclosed for purposes of categorizing and counting layers, and detonating explosives upon reaching a pre-determined location. The method/system includes detecting a deceleration threshold, and enabling a delayed detonation program that may include hard layer counting, void counting, or both. Once the pre-programmed number and/or sequence of layers and voids is detected by the Biggs' system, the weapon is detonated. Biggs, however, fails to transmit to a remote location a signal representing the deceleration encountered by the weapon, and further fails to analyze information regarding the deceleration to identify the material make-up of the structural layers encountered by his weapon. The present invention, on the other hand, returns valuable information regarding layer structure to a remote location so that the material make-up of unknown layers can be identified and, as your inventor has discovered, does not need to measure velocity to make such identifications.
Other than the present invention, none of the foregoing technologies generate a signal or value useful in the identification of the specific materials that make up layers of a target or geological media. Furthermore, there is a need for this technology so that terra-craft can travel to remote locations to determine geological makeup. This would be particularly helpful in space exploration, where present sampling of geological layers near a landing site provides inaccurate data, as the landing contaminates the site and spoofs the investigation of planetary makeup. Thus, the present invention provides signal processing means that can generate and process a deceleration signal to identify specific geological materials, and reliably act on this information by, for example, placing a sensor or detonating explosives at a particular location. The present invention further provides for a more sensitive layer detection system than one designed based upon the minimal disclosure in Biggs.